The present invention relates generally to the field of environmentally sensitive monitoring of aquatic species and habitats. The weaknesses of current monitoring methods used to determine status and trends in fish populations have been known for many years. Currently, monitoring techniques such as trawls, tow nets, and beach seines are used. However, these techniques are generally habitat-specific and of limited range, among other aspects. Trawls and tow nets can sample relatively large areas but are only effective in deep channels and cannot be used in backwaters or shallows, whereas seines can only sample relatively small areas in shallow water and cannot be used effectively in deeper, open water. For instance, the system described in U.S. Pat. No. 6,568,341 is not adequately applicable to deep water sampling. The system described in U.S. Pat. No. 6,306,350 does not adequately address the sample collection needs or the variability needed. The system described in U.S. Pat. No. 5,722,196 is not adequately applicable to deep or open water sampling. The system described in U.S. Pat. No. 8,286,513 is not adequately applicable to the sampling of larger aquatic species. The system described in U.S. Pat. No. 4,554,826 is not adequately applicable to the sampling of varied species. The system described in U.S. Pat. No. 4,446,749 is not adequately applicable to the sampling of varied species and may not be appropriate for the desired sampling in shallower water.
Perhaps one of the most significant problems that scientists and managers have faced is the efficient monitoring of fish populations in estuarine areas. Current monitoring in these areas relies almost exclusively on trawls employed in relatively large, deep channels. These trawls are known to have poor or unknown efficiency and are difficult to relate to habitat conditions important to pelagic fishes. Since trawls are not suited to the sampling of shoals, shallows, inter-tidal, or sub-tidal habitats—which are increasingly recognized as critical habitat for many sensitive estuarine species—beach seining is often used to sample in these areas. However, this method requires shore access and smooth, sparsely vegetated substrates, which can limit the areas in which it can be employed.
At least four additional problems have presented themselves from the perspective of scientists and managers. First, current methods of sampling have limited effectiveness in sampling larval species or other small organisms such as zooplankton and phytoplankton.
A second problem is that current techniques suffer from a lack of data integration. For example, biological sampling using current techniques is often done by passing a net through the water to collect, identify, and catalog fish and other aquatic organisms, and then placing water quality sensors in the water, waiting for them to acclimate, and then taking a reading. This process precludes the simultaneous collection of organisms and data regarding the environment from which they are collected. Further, the employment of multiple sampling methods (e.g., trawls for deep water, seines for shallow water), each over limited geographic areas and each with different efficiencies, makes it difficult to reliably estimate basic metrics such as population size and structure.
A third problem is that current monitoring techniques are costly and time consuming. For example, trawls typically involve towing nets which direct fish and other aquatic organisms into a collection device which must be recovered to identify and enumerate organisms such as fish and invertebrates—a process which requires extended periods of sampling downtime.
A fourth problem is that current methods of sampling often cause excessive injury or mortality of ESA-listed fish or other sensitive species, which can become trapped or entangled by the nets.
In addition to the four specific issues described above, a wide variety of other problems exist in the field as it stands. These include, but are not limited to, sample accuracy, cost of materials, cost of labor, repairs, and environmental degradation, among others.